The present invention relates in general to printing devices such as postage meters, and in particular to a new and useful setting mechanism for the type wheels of such printing devices.
In the presently conventionally used postage meters (or so called franking machines), e.g. the "FRAMA Mod. 100 electronic" of the assignee of the present application, there is a setting mechanism for each type wheel and this is formed from numerous difficult to manufacture and hard to fit components. Each setting mechanism has a rack extending longitudinally through the drive shaft of the franking head, which on the one hand engages with the pinion of the type wheel and on the other with a toothed gear of an adjusting disk rotating with the shaft. On setting the type wheel, a manually operated setting lever is engaged with the adjusting disk and is pivoted about an angle corresponding to the numerical value. By means of the toothed gear arranged in the adjusting disk, this pivoting movement brings about a displacement of the rack and consequently a rotation of the type wheel into the desired setting position. On discontinuing the engagement between the adjusting disk and the setting lever, the setting position in the adjusting disk is secured by stop means. In addition, the adjusting disk is provided with mechanical means, which mechanically operate a counter during each rotation of the franking head and consequently the adjusting disk, said counter counting the value units used up during posting or franking. Details concerning the mechanism used can be gathered e.g. from the spares catalog for the aforementioned machine type.
It has already been proposed to carry out the mechanical adjuting movement in an electromotive manner, but the use of servomotors has led to an even more complicated and voluminous mechanism. However, the use of electrical drives has the advantage that the input of the set values can take place electronically, e.g. also as a function of the electrical signal of a weighing device, because the franking value to be set is also dependent on the weight of the letter or the like to be franked or posted. The electronic input of the set positions for the type wheels also has the advantage that the number of value units used up by the franking operation can be stored in an electronic counter instead of a mechanical counter with reduced expenditure and effort.
As a result of the known purely mechanical setting mechanism for type wheels, it is only possible to set type wheels of a single printing block, i.e. the block for the franking value. The second printing block for the date, normally provided on the circumference of the franking head, must be adjusted manually by means of a tool or by means of a separate so-rotating mechanism after opening the casing cover or flap.